server: support route reflector behavior

scenario_test is also added

Signed-off-by: ISHIDA Wataru <ishida.wataru@lab.ntt.co.jp>

2 files changed, 47 insertions, 5 deletions

diff --git a/table/destination.go b/table/destination.go
index 290830a4..5889fb5b 100644
--- a/table/destination.go
+++ b/table/destination.go
@@ -52,11 +52,13 @@ func CidrToRadixkey(cidr string) string {
 }
 
 type PeerInfo struct {
-	AS      uint32
-	ID      net.IP
-	LocalAS uint32
-	LocalID net.IP
-	Address net.IP
+	AS                      uint32
+	ID                      net.IP
+	LocalAS                 uint32
+	LocalID                 net.IP
+	Address                 net.IP
+	RouteReflectorClient    bool
+	RouteReflectorClusterID net.IP
 }
 
 func (lhs *PeerInfo) Equal(rhs *PeerInfo) bool {
diff --git a/table/path.go b/table/path.go
index 62f0e437..6dbb1f24 100644
--- a/table/path.go
+++ b/table/path.go
@@ -118,6 +118,32 @@ func (path *Path) UpdatePathAttrs(global *config.Global, peer *config.Neighbor)
 		} else {
 			path.pathAttrs[idx] = p
 		}
+
+		// RFC4456: BGP Route Reflection
+		// 8. Avoiding Routing Information Loops
+		info := path.source
+		if peer.RouteReflector.RouteReflectorConfig.RouteReflectorClient {
+			// This attribute will carry the BGP Identifier of the originator of the route in the local AS.
+			// A BGP speaker SHOULD NOT create an ORIGINATOR_ID attribute if one already exists.
+			idx, _ = path.getPathAttr(bgp.BGP_ATTR_TYPE_ORIGINATOR_ID)
+			if idx < 0 {
+				p := bgp.NewPathAttributeOriginatorId(info.ID.String())
+				path.pathAttrs = append(path.pathAttrs, p)
+			}
+			// When an RR reflects a route, it MUST prepend the local CLUSTER_ID to the CLUSTER_LIST.
+			// If the CLUSTER_LIST is empty, it MUST create a new one.
+			idx, _ = path.getPathAttr(bgp.BGP_ATTR_TYPE_CLUSTER_LIST)
+			id := string(peer.RouteReflector.RouteReflectorConfig.RouteReflectorClusterId)
+			if idx < 0 {
+				p := bgp.NewPathAttributeClusterList([]string{id})
+				path.pathAttrs = append(path.pathAttrs, p)
+			} else {
+				p := path.pathAttrs[idx].(*bgp.PathAttributeClusterList)
+				p.Value = append([]net.IP{net.ParseIP(id).To4()}, p.Value...)
+				path.pathAttrs[idx] = p
+			}
+		}
+
 	} else {
 		log.WithFields(log.Fields{
 			"Topic": "Peer",
@@ -582,6 +608,20 @@ func (path *Path) SetMed(med int64, doReplace bool) error {
 	return nil
 }
 
+func (path *Path) GetOriginatorID() net.IP {
+	if _, attr := path.getPathAttr(bgp.BGP_ATTR_TYPE_ORIGINATOR_ID); attr != nil {
+		return attr.(*bgp.PathAttributeOriginatorId).Value
+	}
+	return nil
+}
+
+func (path *Path) GetClusterList() []net.IP {
+	if _, attr := path.getPathAttr(bgp.BGP_ATTR_TYPE_CLUSTER_LIST); attr != nil {
+		return attr.(*bgp.PathAttributeClusterList).Value
+	}
+	return nil
+}
+
 func (lhs *Path) Equal(rhs *Path) bool {
 	if rhs == nil {
 		return false